Method of coloring hair using cationic dyes

Abstract

The cationic dyes of formula (1) specified in claim 1 are suitable especially for coloring keratin-containing fibers, more especially for coloring hair.

1. A method of colouring keratin-containing fibres that comprises treating the fibres with a dye of formula 
                 
 
       wherein
 Y 1  and Y 2  are each independently of the other hydrogen, unsubstituted or substituted C 1 -C 4 -alkyl, or halogen,  
 R 1  and R 2  are each independently of the other hydrogen or unsubstituted or substituted C 1 -C 4 alkyl,  
 R 3  and R 4  are each independently of the other hydrogen, unsubstituted or substituted C 1 -C 4 -alkyl, C 1 -C 4 alkoxy or halogen,  
 R 5  is hydrogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy or halogen,  
 X is C 1 -C 12 alkoxy or a group of formula —N(R 6 )—CO—R 7 , wherein R 6  is hydrogen or C 1 -C 4 alkyl and R 7  is hydrogen, C 1 -C 4 alkyl or —NH 2  and  
 A −  is an anion,  
 With a proviso that Y 1  and Y 2  are each independently of the other not hydrogen atom when R 3  and R 4  are each independently of the other methoxy group.  
 
     
     
       2. A method according to  claim 1 , wherein Y 1  and Y 2  are each independently of the other methyl or hydrogen. 
     
     
       3. A method according to  claim 1 , wherein R 1  and R 2  are each independently of the other ethyl, hydroxyethyl or methyl. 
     
     
       4. A method according to  claim 1 , wherein R 3  and R 4  are each independently of the other methoxy, methyl, hydrogen or chlorine. 
     
     
       5. A method according to  claim 1 , wherein R 5  is hydrogen. 
     
     
       6. A method according to  claim 1 , wherein X is unsubstituted C 1 -C 4 alkoxy or a radical —NH—CO—R 7 , wherein R 7  is hydrogen, methyl, ethyl or —NH 2 . 
     
     
       7. A composition for colouring keratin-containing fibres, which comprises at least one dye of formula (1) 
                 
 
       wherein
 Y 1  and Y 2  are each independently of the other hydrogen, unsubstituted or substituted C 1 -C 4 -alkyl, or halogen,  
 R 1  and R 2  are each independently of the other hydrogen or unsubstituted or substituted C 1 -C 4 alkyl,  
 R 3  and R 4  are each independently of the other hydrogen, unsubstituted or substituted C 1 -C 4 -alkyl, C 1 -C 4 alkoxy or halogen,  
 R 5  is hydrogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy or halogen,  
 X is C 1 -C 12 alkoxy or a group of formula —N(R 6 )—CO—R 7 , wherein R 6  is hydrogen or C 1 -C 4 alkyl and R 7  is hydrogen, C 1 -C 4 alkyl or —NH 2  and  
 A −  is an anion,  
 With a proviso that Y 1  and Y 2  are each independently of the other not hydrogen atom when R 3  and R 4  are each independently of the other methoxy group.  
 
     
     
       8. A composition according to  claim 7 , which additionally comprises at least e oxidation dye or direct dye.